1. Field of the Invention
The invention relates to a method for the determination of sources of danger, primarily such in the region of railways, and especially an early warning system for the detection of approaching railway vehicles.
The persons which are concerned with the carrying out of work and are present in the zone of the tracks for railway vehicles, are permanently exposed to the danger of accidents through the railway vehicles. In addition to human neglect or error, there is also encountered an important ground for accidents through the lack of attention to an acoustic and/or optical alarm signal which would alert the persons to leave the danger zone.
The personnel which are present in the track zone; for example, such as track workers, are subjected to considerable stresses caused through heavy physical work, noise, dust and high or, respectively, low temperatures. In addition thereto, encountered as a further difficulty for the personnel, is the fact that the modern high speed trains approach extremely rapidly and relatively silently towards a track construction site. The safety posts which must trigger a siren as soon as they have visual contact with an approaching train, at least with respect to construction sites at express traffic lines, are unable to provide an adequate preliminary warning period for the endangered personnel. A further problem resides in the loads on the safety posts through inadequate or low demands. The lengthier inactivity in the pauses between trains reduces the alertness of the security posts to such an extent that they will frequently detect an approaching train only belatedly, and as a result the siren is actuated too late.
Safety posts can be integrated into the official railway train reporting chain, and connected by long distance telephone with the applicable railway service supervisor. Notwithstanding the foregoing, a track building site, due to the necessary deviation of the normally introduced operating modalities, presents a positively increased risk in the operation of the railroad. The cause for a few accidents in the past were, for example, errors in reporting the transmission of the reporting of trains, independent deviations of operating personnel on railway vehicles from the content of an already transmitted train report, or timewise earlier then for the applicable railway service, a reported receipt of the building activities in the track zone.
Already in the region of the German Railway alone there are operated each day approximately 3,000 building sites for track construction and track repair or maintenance work. Notwithstanding a massive utilization of research means it has heretofore been impossible to develop and to install an optimized safety system for endangered personnel in the zone of the rails.
2. Discussion of the Prior Art
From German Petty Patent DE 9314495 U1 there has become known an electronic arrangement for the warning of track construction workers of approaching trains, in which a vibration receiver detects the vibrations in the rails upon the passing thereover by a train, and transmits this to a signal evaluating arrangement. Computed in the evaluating arrangement are the different train parameters and upon cognizance of the source of danger, there are activated the different warning installations. The computation of the train parameters in the evaluating arrangement is carried out in dependence upon the signal transmission time between a first and a second vibration receiver.
German Patent Specification DE 4214271 A1 discloses a method for the determination of sources of danger and for the emission of acoustic and/or optical warning signals for persons which are present in the danger zone. The source of danger; for example, a train, is detected by means of acoustic body sound sensors. The signals which are emitted from these body sound-sensors are amplified and, thereafter, transmitted to an alarm installation for the emission of warning signals.